This invention relates to food processing machinery and particularly to sheeting heads that are characterized by a pair of rollers through which a supply of prepared dough is formed into a continuous sheet thereof. For example, tortillas and various chips and the like are made from corn flour referred to as "masa", and in the processing sheets of masa difficulties arise in the separation of the formed sheet from one roller to another as the sheet progresses continuously forward during the food processing. Specifically, the masa sheet must be separated from a back roller and transferred onto a front roller.
Sheeting heads used in the processing of masa and like doughs employ stripper wires that separate the formed sheet from the rollers, as may be required. The typical sheeting head is comprised of back and front rollers disposed on horizontally spaced parallel axes, with the requirement that the formed sheet of dough be stripped from the back roller and transferred onto the front roller, and from the front roller to other rollers such as a cutting mold roller, etc., for forward transport and further processing. Wires have been used for this stripping function, but with ever attendant necessity of position adjustment, due to variations in sheet thickness and variations in the physical properties of the dough. That is, the coarseness and adhesive properties of the doughy mass varies, so as to require constant attention to placement of the stripper wires. Although stripper wires are used in combination with each of the various rollers, including the back and front rollers, and the various other rollers, this invention will be shown and described herein as it is combined with the back roller, a most critical combination.
In practice, the back roller has a convexly cambered face juxtaposed to a complementary concavely cambered face of the front roller. The opposed roller faces are textured so as to have traction with the doughy mass, and the stripper wire engages the roller face from which the formed sheet of dough is to be removed or stripped, in this case the convex face of the back roller. This convexity ensures coextensive engagement of the stripper wire with the back roller face, by tensioning the wire tangentially to the opposite end peripheries of said roller. Variations in sheet thickness requires repositioning of the stripper wire as does variations in the physical properties of the doughy mass. That is, the point of separation of the formed sheet of dough is critical with respect to position of the stripper wire, and this position requirement is also critical with respect to those physical properties.
Typical stripper wire is 0.016 to 0.020 inch diameter, of high grade steel piano wire. In practice, this wire is tensioned horizontally and immediately below the desired point of separation between the formed sheet of dough and the face of the roller from which it is being separated.
Heretofore, prior art stripper wires have been adjusted incrementaly by trial and error, and with the sheeting head out of operation. In other words, the food processing is shut down while adjustments are made, and which is time consuming. Typically, the prior art provides notches for incremental adjustment of the stripper wires at opposite ends of the roller, and this requires loosening of the stripper wire followed by its re-positioning and subsequent re-tightening during said shut down time. These adjustments are required many times during the sheeting process and heretofore has resulted in countless hours of down-time while the machine operator seeks to find a satisfactory stripper wire position, all by trial and error method. For each satisfactory adjustment of the stripper wire, several attempts are usually made. Therefore, it is an object of this invention to provide infinitely variable stripper wire adjustment during machine operation without trial and error selection and without shut down time.
With this invention, it is the vertical position of the stripper wire which is adjusted during machine operation, all of which is executed in a matter of moments without stopping the sheeting process. The adjustment is coordinated dynamically with the sheeting process, without shut down and no down time, and all of which substantially if not entirely eliminates waste and/or recycling of the dough as has been previously required during the stripper wire adjustments.